The invention relates to cloned DNA sequences hybridizable to genomic RNA and DNA of lymphadenopathy-associated virus (LAV), a process for their preparation and their uses. It relates more particularly to stable probes including a DNA sequence which can be used for the detection of the LAV virus or related viruses or DNA pro-viruses in any medium, particularly biological, samples containing any of them.
Lymphadenopathy-associated virus (LAV) is a human retrovirus first isolated from the lymph node of a homosexual patient with lymphadenopathy syndrome, frequently a prodrome or a benign form of acquired immune deficiency syndrome (AIDS) (cf. 1). Subsequently, other LAV isolates have been recovered from patients with AIDS or pre-AIDS (cf. 2-5). All available data are consistent with the virus being the causative agent of AIDS (cf. 11).
The virus is propagated on activated T lymphocytes and has a tropism for the T-cell subset OKT4 (cf. 2-6), in which it induces a cytophatic effect. However, it has been adapted for growth in some Epstein-Barr virus transformed B-cell lines (cf. 7), as well as in the established T-lymphoblastic cell line, CEM.
LAV-like viruses have more recently been independently isolated from patients with AIDS and pre-AIDS. These viruses called HTLV-III (Human T-cell Leukemia/Lymphoma virus type III (cf. 12-15) and ARV (AIDS-associated retrovirus) seem to have many characteristics similar to those of LAV and it is thus probable that they represent independent isolates of the LAV prototype.
Detection methods so far available are based on the recognition of core proteins. Such a method is disclosed in European application titled “Antigenes, moyens et methode pour le diagnostic de lymphadenopathie et du syndrome d'immunodepression acquise” filed on Sep. 14, 1984, under the priority of British application Serial Nr. 83 24800, filed on Sep. 15, 1983. As a matter of fact, a high prevalence of anti-p25 antibodies has been found in the sera of AIDS and pre-AIDS patients and to a lesser but significant extent in the high-risk groups for AIDS (cf. 8-10). However, the same sera were found not to recognize the virus as a whole, in a non-disintegrated state.